We are investigating the role of cellular factors that mediate signal transduction in the regulation of viral gene expression. We analyzed the expression of the cellular oncogenes c-fos, c-myc and v-src ( a tyrosine kinase expressed in T-cells) in human peripheral blood lymphocytes (PBLs) and H9 and U937 cells following infection with HIV-1. Quiescent PBLs were infected with HIV-1 using serum-free medium in the presence or absence of IL-2. At various times after infection DNA and RNA were analyzed for the presence of viral and oncogene sequences and cells were fixed for analysis of antigen by flow cytometry. A 20 fold increase in c-fos RNA and a 4-5 fold increase in c-fos antigen was observed between 2 and 22 hours post-infection. This increase was inhibited by actinomycin D. In these same cells, HIV-1 sequences were first detected in genomic DNA at 2 hours and viral transcripts between 2 and 4 hours post-infection. Our preliminary results suggest that enhancement of the expression of some of these cellular oncogenes may play a role in regulating viral replication in infected cells. Similar studies are in progress with HUT-78 and CEM cells infected with HIV-2. Experiments evaluating the role of tranfected c-fos and c-jun (another cellular oncogene) in the transactivation of the HIV genome are in progress. Gel retardation assays and UV cross linking studies are being performed to study these factors. We also plan to study the effects of anti-HIV agents on cellular kinases in HIV-1 and HIV-2 infected cells. These studies will enable us to further define the stages of viral replication at which these gene products may function.